This invention relates to a walk-behind lawn mower, and more particularly to an improved height adjusting, discharge chute and drive arrangement for such a lawn mower, as well as for an improved construction for providing a more uniform cut for such a lawn mower.
A common type of lawn mower is the so-called "rotary type". With this type of mower, the cutting blade rotates about a vertically disposed axis and is contained within a scroll-shaped outer housing that has an opening which forms a discharge chute through which the cut grass is discharged. This type of lawn mower may be either side or rear discharge type. A disadvantage with the side discharge type is that the catcher bag, which is attached to the side of the lawn mower, obstructs the ability of the mower to be placed close to objects such as trees, curbing or the like and thus substantially diminishes the utility of the mower.
Although a rear discharge type of mower overcomes these difficulties, there are certain other problems with the design of rear discharge rotary mowers. One of these has to do with the driving arrangement for the rear wheels, if the mower is of the self-propelled type. If both rear wheels are driven, the shaft for the rear wheels is positioned at a height such that it is in proximity to and extends across the discharge chute opening of the mower. As such, the flow of grass discharge is obstructed and, furthermore, grass may accumulate either on the axle shaft or on its outer housing to further clog the discharge opening. Furthermore, this location for the axle shaft tends to cause the grass clippings to impinge upon and become clogged in the drive arrangement for the axle.
It is, therefore, a principle object of this invention to provide an improved drive and chute arrangement for a self-propelled lawn mower.
It is a further object of this invention to provide an improved rear discharge, self-propelled rotary type of lawn mower.
It is another object of this invention to provide a driving arrangement for a rotary lawn mower when the driving arrangement will not interfere with the grass discharge and will not become contaminated by the grass that has been cut.
In connection with rotary type lawn mowers, they are normally provided with four independently adjustable wheels. Adjustment of the wheels relative to the mower housing accomplishes the cutting height adjustment. Although arrangements have been incorporated wherein more than one wheel may be adjusted simultaneously, when the mower is of the type having powered wheels, the manner of adjustment becomes very complicated. This is particularly true when pairs of wheels are coupled together through a driven axle and those wheels must have their height adjusted. The problem becomes even more acute when the adjustment is achieved in combination with the rear driven wheels of a rear discharge rotary motor.
It is, therefore, a still further object of this invention to provide an improved adjusting arrangement for the driven wheels of a lawn mower.
It is a further object of this invention to provide an improved wheel height adjustment for a rear discharge rotary lawn mower.
One of the disadvantages of certain types of rotary mowers is that they do not provide a uniform cut of the grass. The reason for this is that the motion of the blade is utilized to attempt to cause the grass to maintain an erect position so that it will be cut uniformly. However, with certain types of grasses or certain conditions, this construction, per se, is not sufficient so as to cause all of the grass to be held erect when being cut.
It is, therefore, a still further object of this invention to provide an improved cutting arrangement for a rotary type lawn mower that will insure that the grasses are erect before they are cut.